- SUBMERSION INJURY -

Question 1

Describe the pathophysiology of submersion injuries

Answer 1

 Initial submersion causes voluntary apnoea

 Hypoxia & hypercapnia eventually cause an involuntary breath to be taken
– Water aspirated

 If conscious, victim may panic / struggle

– ↑HR & BP, thereby ↑ O2 consumption
Swallowing of air & water, often in large amounts

– Causes vomiting, which may be aspirated into lungs

 Respiratory impairment causes brain hypoxia, leading to LOC and cessation of breathing efforts

 As hypoxia continues, HR & BP begin to fall, progressing to cardiac arrest

Question 2

Discuss the difference between dry and wet drowning

Answer 2

DRY DROWNING

• cold water triggers laryngospasm
• lungs are dry
• hypoxia
• LOC

WET DROWNING

• 90% of drownings
• aspiration of water
• diminished gas transfer
• atelectasis
• V/Q mismatch

Question 3

Differentiate between fatal and non-fatal drowning

Answer 3

Fatal
- person dies during any stage of the drowning process

Non-fatal
- drowning process interrupted and person does not die

Question 4

Define secondary drowning

Answer 4

• survives drowning for >24hrs
• death due to chemical or structural changes after near-drowning
  e. g. brain damage, electrolyte disturbances, pulmonary oedema

Question 5

Discuss the management of a patient post submersion injury

Answer 5

Airway:
 Foam in mouth & airways is common
– Intubation if:
 Neurological deterioration
 Unable to maintain PaO2 above 60mmHg or SpO2
above 90%
 PaCO2 above 50mmHg

Breathing:
 Foam in mouth & airways is common
– Intubation if:
 Neurological deterioration
 Unable to maintain PaO2 above 60mmHg or SpO2
above 90%
 PaCO2 above 50mmHg

Circulation:
– Rapid, warm IV fluids if prolonged immersion

Disability
– Hypothermia
– Remove wet clothing
– Active / passive re-warming
– NGT
– Broad spectrum antibiotics if signs of infection
– Close observation for 6hrs

In unwitnessed drowning, consider causes:
– Spinal injury while in water
– AMI while swimming
– Seizures
– Drugs & alcohol
– Low BSL